• Title/Summary/Keyword: fermentation control

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A Study on the Conditions of Demethyltetracycline Fermentation (Demethylteracycline 발효조건에 관한 연구)

  • 최남희;장덕진;양한철;양한철
    • Microbiology and Biotechnology Letters
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    • v.20 no.2
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    • pp.203-206
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    • 1992
  • Conditions of fermentation for the production of demethyltetracycline were examined using the mutant, which was obtained through the cell fusion of demeclocycline producing strains, The optimum temperature and the initial pH of broth for demethyltetracycline fermentation were $25^{\circ}C$ and 6.7, respectively. Unlike any other cases, the control of pH with alkali solution during the fermentation process affected the productivity. As a general rule, the larger the inoculum size the higher the early consumption of sugar and the viscosity of broth, which means that fermentation proceeds more rapidly as the inoculum size is increased. The highest productivity was shown when the inoculum size was 5% (v/v), and the phase of seed also influenced the fermentation. Among the parameters of pre-culture thus examined, pH was the most important factor.

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Effects of Protein Sources on Kimchi Fermentation and on the Stability of Ascorbic Acid (단백질(蛋白質) 급원(給源) 식품(食品)이 김치의 발효와 Ascorbic Acid의 안정도(安定度)에 미치는 영향(影響))

  • Lee, H.S.;Ko, Y.T.;Lim, S.J.
    • Journal of Nutrition and Health
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    • v.17 no.2
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    • pp.101-107
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    • 1984
  • Effects of protein-sources on Kimchi fermentation and on the stability of ascorbic acid were investigated at $7{\pm}1^{\circ}C.$ Kimchi samples with various protein sources showed the higher pH and total acidity through the fermentation period than kimchi without the proteins. The results revealed that the proteins have acted as good buffer and lactobacilli-growth enhancer in the fermentation, and the milk proteins showed the most significant effect among the samples. The lactobacilli were at the highest growth at 15th day in all the samples. The amounts and changes in ascorbic acid content during the fermentation did not differ significantly between the control and protein added samples. The fresh, unfermented kimchi contained 14.5-15.7mg of ascorbic acid per 100g of sample and decreased continuously by the 12th day of fermentation. After then the vitamin increased in all the samples and then again decreased slowly after 18th day. The contents of ascorbic acid at the end of the 3 weeks-fermentation(16.3-17.3mg/100g) were still higher than the contents of fresh, unfermented kimchi.

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A Study on the Reduction of Gossypol Levels by Mixed Culture Solid Substrate Fermentation of Cottonseed Meal

  • Zhang, Wenju;Xu, Zirong;Sun, Jianyi;Yang, Xia
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.9
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    • pp.1314-1321
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    • 2006
  • The objective of this work was to study the effect of mixed culture solid substrate fermentation of C. tropicalis ZD-3 with A. niger ZD-8 on detoxification of cottonseed meal (CSM), and to investigate the effect of fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment on the reduction of free gossypol levels during mixed culture solid substrate fermentation of CSM. Experiment 1: Three groups of disinfected CSM substrate were incubated for 48 h after inoculation with either of the fungi C. tropicalis ZD-3, A. niger ZD-8 or mixed culture (C. tropicalis ZD-3 with A. niger ZD-8). One non-inoculated group was used as the control. Levels of initial and final free gossypol (FG), CP and in vitro CP digestibility were assayed. The results indicated that mixed culture fermentation was far more effective than single strain fermentation, which not only had higher detoxification rate, but also had higher CP content and in vitro digestibility. Experiment 2: CSM substrates were treated according to experimental variables including fermentation period, proportion of CSM in substrate, sodium carbonate, minerals and heat treatment, Then, the treated CSM substrates were inoculated with mixed culture (C. tropicalis ZD-3 with A. niger ZD-8) and incubated at $30^{\circ}C$ for 36 h in a 95% relative humidity chamber. After fermentation ended, FG and CP content of fermented CSM substrate was assayed. The results showed that the appropriate fermentation period was 36 h, and the optimal proportion of CSM in substrate was 70%. Addition of sodium carbonate to CSM substrate was beneficial for fermentative detoxification. Heat treatment could facilitate fermentative detoxification, and supplementation with minerals was instrumental in reducing gossypol levels during mixed culture solid substrate fermentation of CSM.

Characteristics of Yeast Flora and Gas Generation during Fermentation of Doenjang (된장의 발효숙성에 관여하는 효모의 분포와 가스발생 특성)

  • Oh, Nam-Soon;Lee, Nam-Suk
    • Applied Biological Chemistry
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    • v.39 no.4
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    • pp.255-259
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    • 1996
  • In order to improve the quality of commercially manufactured Doenjang, yeast florae, gas and alcohol formation during fermentation of Doenjang were periodically examined. Candida rugosa, Candida zeylanoides, Pichia farinosa Saccharomyces cerevisiae and Zygosaccharomyces rouxii were isolated and identified from Doenjang at various fermentation stage. S. cerevisiae and Z. rouxii showed distintive gas and alcohol formation activities and the distribution ratio of Z. rouxii was 26% at 14 days and 76% as prevailed yeast strain after 30 days fermentation, respectively. Ethanol content of Doenjang was gradually increased into 2.19% at final stage of fermentation. The amount of gas generated during fermentation was 9.75 ml/g after 14 days, 4.5 ml/g after 30 days and decreased into negligible amount after 45 days fermentation. These inhibitory effects on gas generation by fermentation period would be ascribed to the ethanol Produced for fermentation. This results suggest that gas generation in commercially manufactured Doenjang could be eliminated through the effective control of fermentation by yeast without application of any preservatives.

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Sensory Evaluation and Changes in Microflora and Enzyme Activities of Red Ginseng Kochujang (홍삼첨가 고추장의 관능적 특성 및 미생물과 효소력이 변화)

  • 신현주;신동화;곽이성;주종재;유정희
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.4
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    • pp.766-772
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    • 1999
  • In order to improve funtionality of kochujang, red ginseng powder(1, 2 and 5% red ginseng on the total weight basis) was added to the raw material of kochujang. Changes in moisture content, microflora and enzyme activities were investigated in control kochujang(Sunchang kochujang) and red ginseng added kochujang during fermentation at 25oC for 120 days. Kochujang samples fremented for 90 and 120 days were subjected to sensory evaluation test. As the fermentation progressed, the moisture content and titratable acidity were gradually increased whereas pH was decreased. However, red ginseng had no effects on those changes. Bacterial count was maintained at the level of 107 CFU/g during fermentation. The level of yeast count was 104 CFU/g at the early stage of fermentation and increaed to 107 CFU/g after 60 days of fermentation and then maintained at 107 CFU/g. Red-ginseng had no effects on bacterial and yeast counts of kochujang. Amylase activity was gradually reduced during fermentation. Amylase activity was increased until 60 days of fermentation and then reduced by 90 days of fermentation. Acidic protease activity was slightly reduced at the initial stage of fermentation and then rapid increased. Acidic protease activity was at the highest level after 120 days of fermentation. Red ginseng did not alter those enzyme activities of kochujang. There were no differences in sensory properties between kochujang samples fermented for 90 and 120 days of fermentation. The addition of red-ginseng did not affect such sensory properties of kochujang as color, odor, hot taste and salty taste, but overall preference appeared to be improved by red ginseng addition.

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Effect of Korean red ginseng marc fermented by Bacillus subtilis on swine immunity

  • Kim, Hong-Kook;Choe, Yeong-Ho;Kim, Geun-Seop;Kim, Ha-Young;Kim, Byeong-Soo
    • Korean Journal of Veterinary Service
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    • v.41 no.3
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    • pp.141-147
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    • 2018
  • Red ginseng marc is a by-product of Korean red ginseng (panax ginseng CA Meyer) and contains ginsenoside which has pharmacological effects. The Korean red ginseng marc was fermented with Bacillus subtilis (RGMB). This study was carried out to investigate the RGMB effect on swine immunity. The variation of ginsenoside depending on the RGMB fermentation time was analyzed. Swine (Landrace${\times}$Yorkshire) were divided into control group (basic diet) and RGMB group (RGMB 1% diet). One percent RGMB was fed to the RGMB group for 28 days. The biochemical parameters, cytokine and immunoglobulin were analyzed. For 48 hours of fermentation on RGMB, ginsenoside Rb1 had increased 180.94%, Rg3 235.85%. Rg1 wasn't detected before fermentation, but was detected after 48 hours of fermentation. The RGMB had effect of deceasing initial AST concentration $79.33{\pm}12.85U/L$ to $54.00{\pm}14.46U/L$ in final and was significantly lower (P<0.05) than control in final. In final RGMB had significantly lower (P<0.05) ALT concentration of $48.57{\pm}8.26U/L$ comparing with control group of $65.43{\pm}10.31U/L$. RGMB had the effect of significantly decreasing (P<0.05) $IL-1{\beta}$, IL-6 and $TNF-{\alpha}$ concentration of $2.44{\pm}1.31ng/mL$, $0.71{\pm}0.36ng/mL$ and $0.51{\pm}0.21ng/mL$. The IgA concentration had significantly increased (P<0.05) in RGMB group of $0.56{\pm}0.06mg/mL$ in final. These results demonstrate that RGMB has effect of increasing immunity and practicable to use as feed additives on swine.

The Effects of Thyme and Cinnamon Essential Oils on Performance, Rumen Fermentation and Blood Metabolites in Holstein Calves Consuming High Concentrate Diet

  • Vakili, A.R.;Khorrami, Behzad;Mesgaran, M. Danesh;Parand, E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.7
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    • pp.935-944
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    • 2013
  • Essential oils have been shown to favorably effect in vitro ruminal fermentation, but there are few in vivo studies that have examined animal responses. The objective of this study was to evaluate the effects of thyme (THY) and cinnamon (CIN) essential oils on feed intake, growth performance, ruminal fermentation and blood metabolites in feedlot calves fed high-concentrate diets. Twelve growing Holstein calves ($213{\pm}17kg$ initial BW) were used in a completely randomized design and received their respective dietary treatments for 45 d. Treatments were: 1-control (no additive), 2-THY (5 g/d/calf) and 3-CIN (5 g/d/calf). Calves were fed ad libitum diets consisting of 15% forage and 85% concentrate, and adapted to the finishing diet by gradually increasing the concentrate ratio with feeding a series of transition diets 5 wk before the experiment started. Supplementation of THY or CIN did not affect DMI and ADG, and feed efficiency was similar between treatment groups. There were no effects of additives on ruminal pH and rumen concentrations of ammonia nitrogen and total VFA; whereas molar proportion of acetate and ratio of acetate to propionate decreased, and the molar proportion of propionate increased with THY and CIN supplementation. Rumen molar concentration of butyrate was significantly increased by adding CIN compared to control; but no change was observed with THY compared with control group. No effects of THY, or CIN were observed on valerate, isobutyrate or isovalerate proportions. Plasma concentrations of glucose, cholesterol, triglyceride, urea-N, ${\beta}$-hydroxybutyrate, alanine aminotransferase and aspartate aminotransferase were not changed by feeding THY or CIN. Results from this study suggest that supplementing a feedlot finishing diet with THY or CIN essential oil might be useful as ruminal fermentation modifiers in beef production systems, but has minor impacts on blood metabolites.

A Non-yeast Kefir-like Fermented Milk Development with Lactobacillus acidophilus KCNU and Lactobacillus brevis Bmb6

  • Lee, Bomee;Yong, Cheng-Chung;Yi, Hae-Chang;Kim, Saehun;Oh, Sejong
    • Food Science of Animal Resources
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    • v.40 no.4
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    • pp.541-550
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    • 2020
  • The use of yeast assist kefir fermentation, but also can cause food spoilage if uncontrolled. Hence, in this study, the microbial composition of an existing commercial kefir starter was modified to produce a functional starter, where Lactobacillus acidophilus KCNU and Lactobacillus brevis Bmb6 were used to replace yeast in the original starter to produce non-yeast kefir-like fermented milk. The functional starter containing L. acidophilus KCNU and L. brevis Bmb6 demonstrated excellent stability with 1010 CFU/g of total viable cells throughout the 12 weeks low-temperature storage. The newly developed functional starter also displayed a similar fermentation efficacy as the yeast-containing control starter, by completing the milk fermentation within 12 h, with a comparable total number of viable cells (108 CFU/mL) in the final products, as in control. Sensory evaluation revealed that the functional starter-fermented milk highly resembled the flavor of the control kefir, with enhanced sourness. Furthermore, oral administration of functional starter-fermented milk significantly improved the disease activity index score by preventing drastic weight-loss and further deterioration of disease symptoms in DSS-induced mice. Altogether, L. acidophilus KCNU and L. brevis Bmb6 have successfully replaced yeast in a commercial starter pack to produce a kefir-like fermented milk beverage with additional health benefits. The outcome of this study provides an insight that the specific role of yeast in the fermentation process could be replaced with suitable probiotic candidates.

Effect of $CaCO_3$ on the Chonggukchang Meju Fermentation by B. subtilis ($CaCO_3$가 Bacillus subtilis에 의한 청국장메주 발효에 미치는 영향)

  • Lee, Kang-Moo;Lee, Si-Kyung;Joo, Hyun-Kyu
    • Applied Biological Chemistry
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    • v.37 no.6
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    • pp.421-426
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    • 1994
  • This study was carried out to investigate the effect of $CaCO_3$ on the Chungkookjang Meju fermentation. B. subtilis was cultured on the Meju added 0, 0.01, 0.1, 1% $CaCO_3$, respectively, and the chemical composition, protease activity, amino acid and vitamin B complex were examined with fermentation time. The inner temperature of the $CaCO_3$ treatments during fermentation was increased as compared with the control group. Titratable acidity in Meju decreased as $CaCO_3$ concentration increased. And protease activity and amino-nitrogen content were however high in same order. The content of amino acid was on the increase in every treatments, it made no difference between $CaCO_3$, treatments and the control. Vitamin B complex content in the $CaCO_3$ treatments was increased than in the control. The 0.01% added treatment showed the highest amount of vitamin B complex content in all the treatments.

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Effects of Adding Oyster Crassostrea gigas Shell Powder on the Food Quality of Chinese Cabbage Kimchi (굴(Crassostrea gigas) 패각 분말 첨가에 의한 배추김치의 식품학적 품질 변화)

  • Do, Hyoung-Hun;Kim, Ji-Hoon;Han, Hae-Na;Kim, Song-Hee;Kim, Gab-Jin;Eom, Sung-Hwan;Kim, Young-Mog
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.5
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    • pp.596-603
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    • 2015
  • This study investigated the effects of adding oyster shell powder (OSP) from Crassostrea gigas on the food quality of Chinese cabbage Kimchi (CCK). We monitored the changes in microbial levels, pH, acidity and sensory evaluation during the fermentation of CCK treated with various contents of OSP. The microbial assay showed that adding OSP to CCK inhibited the growth of viable cells, total coliforms, and lactic acid bacteria, with the greatest growth inhibition against lactic acid bacteria over the fermentation period. After fermentation for 18 days, the lactic acid bacterial counts in CCK treated with OSP (0.3%, 0.5% and 1%) were at least 1 log CFU/g lower than those of control CCK. In addition, the pH and acidity of CCK treated with OSP were lower than in control CCK over the fermentation period. The overall sensory evaluation of CCK with 0.3% OSP was better than that of control CCK after fermentation for 24 days. In conclusion, OSP treatment, especially 0.3% OSP, enhances the food quality and extends the self-life of CCK, while minimizing the detrimental effects on its sensory characteristics.